Author(s): , , , ,
Institution(s): 1. Keele University, 2. University of Geneva
The study of stellar populations are of great value to improve the input physics we use in stellar models. In that view, stellar clusters represent coherent populations in age and metallicity, and are thus key targets to be compared with theoretical models. I will present synthetic clusters generated at various ages and with metallicities spanning from the low Z of I Zwicky 18 to super solar ones. I will discuss their properties from a stellar evolution point of view. The metallicity effects on the expected RSG and WR populations are commented. I will then check the validity of the theoretical assumptions with observed young stellar clusters in various environments.